1. Field of the Invention
The present invention relates to a safety seat installed in a motor vehicle, for example, a truck or a car used by passengers, and particularly to the safety seat in the cab for the motor vehicle driver and/or passengers on the front seats. The safety seat includes a common safety belt, a movable seat and sensors. The movable seat is supported on pipe rails by the means of ball rollers and locked by a locking device which is controlled by electromagnetic force. Each of the sensors comprises two sheets which are arrange to be separated from each other by insulation blocks. Alternatively, the sensors may also include a thin wall metal pipe and a cylindrical metal rod inserted in the thin wall metal pipe, between which there is a gap in which insulation rings are arranged. If the motor vehicle collides with an obstruction, the two metal sheets and/or the thin wall metal pipe and the metal rod of the sensor contact each other to close a circuit. Then the locking device will release the seat under the action of electromagnetic force and the seat will be forced to move backward under the action of compressed springs, thereby preventing the driver and/or passengers on the front seat from injury caused by obstructions penetrating into the cab and/or the front seat due to the collision.
The present invention relates to a safety device for a motor car and particularly to a safety seat installed in a motor car.
When a motor vehicle is in a collision, the main cause of the driver or passenger on the front seat being injured is that damaging objects break into or penetrate into the cab or the front seats, and directly injure the driver or passenger on front seat. Another reason is that, when a motor vehicle stops suddenly because of a collision, the body of the driver or passenger bumps against stationary objects in the front of the motor vehicle and injury occurs because of inertia. For example, when the motor vehicle is in a collision, the driver bumps against the steering wheel and passengers on the front seats bump against the windshield and are injured. Therefore, there have been many devices to prevent a human body from bumping in a forward direction caused by the human body's inertia force.
For example, a safety belt is assembled on the seat to belt the human body onto the seat, and to prevent the human body from being injured by a bump forward under the action of inertia force when the motor vehicle is in a collision. In another method, the steering wheel may be made into a deformable structure to prevent the human body from coming into a rigid collision. In a further method, the surfaces of stationary objects in the motor vehicle may be covered with soft materials to alleviate the harm of a collision. None of these methods can prevent a human body from direct injury caused by various damaging objects breaking into or penetrating into the cab or front seats during a collision.
2. Description of Related Art
Chinese patent 89206293.2 provides a driver's seat which is supported by four wheels on two parallel rails in the shape of ]. A locking device is provided on the rails to lock the seat. A mechanical touching-block is arranged in front of a fender-guard. When the mechanical touching-block is damaged in a crash, the locking device is unlocked by several levers connected with the touching-block to release the seat The seat then moves backward under the action of spring forces or other forces to prevent occupants of the vehicle from being injured. This known safety seat has obvious disadvantages in that the mechanical touching-block of the safety seat can be arranged in only one position, and it is impossible to arrange the mechanical touching-block of the safety seat at every portion of the front of the motor vehicle. Thus, when the motor vehicle is in a crash in bevel side or other portion, the touching-block cannot be contacted to make the seat move backward to prevent the occupants from being injured. Moreover, the mechanical touching-block drives the locking device by means of several levers, and the gap between connecting ends of the levers cannot be avoided, which results in the failure to synchronize the release of the seat with the collision of the motor vehicle. It is also possible that occupants are injured because of delay in the seat being moved back. In addition, the seat is supported by wheels on two parallel rails which are required to be exactly parallel, and any slight inclination of the rails may result in locking of the wheels and prevention of a free backward movement of the seat, thus nullifying the safety feature.
Accordingly, the object of the invention is to provide a safety seat in which a pin is driven to unlock a seat which is secured in position, immediately when a motor vehicle comes into collision, to make the seat move backward. The seat is supported by means of ball rollers on pipe rails, and moves backward reliably without obstruction. Especially, sensors can be arranged at any position at which collision may take place on the front of the motor vehicle, so that, no matter what part of the motor vehicle is in the crash, the seat is able to move backward immediately.